Control system for hydraulic apparatus



Nov. 25, 1952 w. J. F. O'CONNOR ETAL CONTROL SYSTEM FOR HYDRAULICAPPARATUS Filed Dec. 5, 1950 {NVENTORS Zara/2117080072011 Fran/triJZowerz, J1:

Patented Nov. 25, 195 2 iUJNIiTIZED :STATII s CONTROL SYSTEMFORA'HYDRAULIC "APPARATUS v Ward JOGomior and Frank Ai Rowen, Jr.,

: Bayonne, N;J., assignorwtm'llhe hummus Gompany; New.-York; N.Y.,-'-1ai;'=corporation ofmDelaware This invention 'relates '-to controlof the opera- I tion of hydraulic appara-tus capable of use in; avariety or services. *An example is the removal ofa hard deposit of coke-from' a coking drum. "-"In such ser-viceit -is common 'practice to use'-'-downwa1"dly directed hydraulic jets to first drill a centralpassagethroughdhe coke deposit and then use jets directed'laterally-outward from -*said passage'to' cutthe coke' into layers to'facilitate its dislodgement and removal through the ""lower end of thedrumf For effective operation of the, jets; hydraulic app iratus capableofdelivering water "at a pressure of approximately-- 1-500-"lbs."--per"sq.- in: is-required. In the' operation of theapparatusyvariations" in pressure and changes 'in direction therofsuchas occur in the-start- -ing"and stoppingof the delivery to the jetscause severe shock' and strain upon the pump and the "piping-oftheapparatus. "The-present invention *"is"concerned"particularlywithcontrol of the-operation of the apparatus *in a-manner-to eliminate "isush shock.

Important objectsof theinvention are; topro- *-'vide an improvedcontrolsystem "for' hydraulic apparatus devised 'to eliminate injuriousshock m the operation thereof rtoprbvide' such asystem" capable ofaccomplishingits'f purpose" with minimum attention from the operator;"'-to provide aisystem responsive to one" setting of a single 'switchd'evice to "cause starting'and build-up of the hydraulic d'elivery'bythe" apparatus-without ""shock' and responsive to "another setting orthe switch device to cause the apparatus to stop deliverywith'out"shock; and" toprovide such a 'sy'stem"with' -efficient pneumaticallyoperable mechanism responsive to the settings of i the ":swit'chdeviceto effecti'said" control of the appa- "Tatus.

TFurther' obj ects" andi'advantages of the invention"Wilfappearfrom the"following description taken in" connection with "the accompanying""'draiwing.

I "IIn'ithe drawing: Fig." 1 is view: partly dia'grammaticgshowlng theimproved control system; operatively connect-"t""edtofhydraulie:apparatus?employed for a' de- "decking". operation.

1 Figi2 is" a'view, partlyidiagrammatic; eta-"porftion of the controlsystem" with the-switch adijiisted to 'stop'hydr'aulic" delivery by theapparatus.

"Accordingrtotheinvention, the normal operaitiono'tith'e'hydraulicfapparatus is under the con- "ftiol:'ot'.a "singleair"'switch"which is settablgto eitherioi' two positions for"starting-or stopping -idelivery' o'f hydraulic.v pressure "by the.apparatus. ""For'starting delivery'by'theapparatustheswitch 2 'iss'et in'one 2'. of said positions and;- rinairesponse to said setting,pneumatically; operable: mechanism is actuated to 'doxthree thingsnamely, -open v.av -valve -in the 'deliver'y line of the-pump, close awalve in A a =by-pass "lineithrough :which -lthecde- 7 livery' line isconnected to the. suction line: of the '-pump', and 1 also' causeincrease of: the rate of operation'ot the pump. Inresponseito the othersetting of the switch the pneumatic mechanism is actuated to causeopening of saidby-passvalve, reduction- I of the s'peed' of the pump andclosing I of the valve in the' delivery line. 'ThIOUgh -SUOh =controlinjurious-"shock is avoided "inAi-both V the starting and'stoppingof thedelivery.

In Fig. 1 the improved control system is shown *as operatively.connected: to ihydraulic apparatus *for- "delivery i of water under highpressure to a jet device employed in a decokingoperation; The apparatus''includes 1 a pump I driven by a steam turbine Z h'avinga hydraulicgovernor; indicated siat 3. 'A hydraulic pipe 4 leads toi the governor 1and-has a: valve 5. delivery pipe 6 leads from the pump and hasa valve'.1.: :Beyond saidxvalve thepipe -6 is in deliveryeonnection(withajet'ide- 25 :vice J 'through the usual rigging-which:enables iilowering and: raising of the: device through; a coke:drum-i D.I The rigging islomitted from vllthe :vridi'awingpto simplifyfthe'il-lustration. A=by lpass 1 conduit iormed: of pipe: sections 8':connected -by an angle valve 'il; leads from the delivery-pipe, at--apoint between" the-pump and' the valve 'L to ia -tank l 0; Thesu-ctionorchargeline l l oi'dzhe "pump'--' leads*fromth bottom of-saidtank to the --pump inlet. A water make-up conduit line fla' le'adsto the" tank.

'The control "system includes a; manually operable'air switch I 2-mounted" for shiftingof one end thereof between' positions A and' B."The fswitch may be mounted in a positionadjacent 40- the 'top" of -thecoking drum for convenient oper- 'ation. 1 It is shown; however;displaced from said i i position -for convenient illustration. air"supply li-ne l 3" leads to 'the- -switchposition--B and has a-manuallysetta-blepressure regulating'valve "H. "'An air line 15 leads"- from'the' switch" to pneumatic mechanism for causing operation '-ofthehydraulimvalves 5, '1 and 9. "Diaphragm 'motors" l6, '|1 'and I8areoperatively connected to the valves 5; 1 and-' 9 respectively;and*are'op- 5Q-erable in"responseto *theswitch settings. Motor I 6" isconn'ected -by an'" air line I 9 to the line '1 5 whichleadsirom the"switch. Said linel5-also leads-toi a four-way' valve device 20. Thisdevice "includes-a" plunger type valve' 2 lreciprocable' to 'control airflow through two spaced-"ports 22 and-'ziiinthe valve'casingand"diaphragm motors Each of the motors I1 and I8 which operate the valves 1and 9 respectively, has chambers at opposite sides of its diaphragm. Anair line 30 leads from the port 22 of the four-way valve device 20 tothe inner diaphragm chamber of motor H. A branch line 3| leads from line30 to the outer diaphragm chamber of motor l8. Another air line 32 leadsfrom port 23 of the four-way valve device to the inner diaphragm chamberof the motor l8, and a branch 33 of line 32 leads to the outer diaphragmchamber of motor l1.

Provision is made for stopping the turbine 2 in an emergency. For thatpurpose, a solenoid device 34 is operatively connected to a valve device35 for controlling admission of steam from the steam line 36 to theturbine. The line 35 also has a manually operable valve 31. The circuit33 of the solenoid has a push-button switch 39 located adjacent the airswitch l2 for convenient operation,

air gauge device 40 is associated with the air switch |2. This devicehas a dial and two pointers 4| and. The pointer 4| is movable inresponse to pressure variations in the line l and the pointer 42 ismovable in response to pressure variations in the line l3.

Preparatory to operating the apparatus, the air line I3 is supplied withair at a pressure of, say lbs. p. s. i. g., and the reducing valve I4 isadjusted to reduce said pressure to adesired loading of say 15 lbs. p.s. i. g. Air pressure at, say 35 lbs. p. s. i. g., is supplied to theline 26 leading to the four-way valve device 29, and'the reducing valve29 reduces the pressure going to the diaphragm motor 25, to, say 5 lbs.p. s. i. g. Then, with the valve 31 of the steam supply line 36 to theturbine closed, the air switch |2 is set in the position indicated at Awhich may-be identified as the Minimum position. Fig.2 shows the switchin thisposition. In this position the switch registers with a vent V toatmosphere and the air escapes from above the diaphragm of,

motor 24 through the line l5, the switch and; said vent. The airpressure beneath the diaphragm of motor then forces the diaphragm andthe valve 2| upward with reference to the drawing. In its elevatedposition the valve admits pres- 1 sure from the line 26, through theport 23 and the lines 32 and 33- to the inner chamber of the motor l8and the outer chamber of motor ll. Simultaneously, the valve 2| ventsto'atmosphere the outer chamber of motor |8-and the inner chamber ofmotor I! through the lines 3|, 30,

the valve port 22 and past the upper portion of valve 2| to atmosphere.Thereby,- the hydraulic by-pass valve 9 is opened and the delivery valve"l isclosed. When the air switch is in the position-shown in Fig. 2, airpressure beneath the diaphragm of the motor i6 escapes through the lineI9, the line-|5, theair switch l2 and the vent The valve 5 is thenoperated toward closed 4 air switch I2 is set in the B position, asshown in Fig. 1. This position may be designated the Maximum position.Air from the line I3 is then admitted through the switch l2, and theline l5 to the upperside of the diaphragm of the motor 24. Thereby, thediaphragm and the valve 2| are forced downward against the resistance ofthe inferior pressure beneath the diaphragm of the motor 25. In itsdepressed position, the valve 2| exhausts to atmosphere the pressurewithin the outer diaphragm chamber of the motor ll, through the lines 33and 32, the port 23 and the lower portion of the valve casing. The innerdiaphragm chamber of motor I8 is also vented to atmosphere through theline 32. At the same time, pressure from the air supply line 2'6 isadmitted through the port 22 and the lines 30 and 3| to the innerdiaphragm chamber of motor I1 and the outer diaphragm chamber of motorl8, to cause opening of the hydraulic delivery valve 1 and closing ofthe by-pass valve 9. In its said Maximum position the air switch alsoadmits pressure from the line |3 through the switch, the line l5 and theline I9 to the under side of the diaphragm of the governor valve motor5. Thereby, the valve 5 is opened to increase the speed of the turbineand obtain th required working delivery by the pump through 'the line 8to the jet device J. i

In order to stop delivery by the hydraulic apparatus it is merelyrequired that the air switch 12 be shifted back to the Minimum position.The pneumatic control system then responds to cause opening of theby-pass valve 9, closing of the delivery valve 1 and'operation of thegovernorvalve 5 to reduce the speed of the turbine and the rate ofoperation of the pump In the intervals between decoking operations thevalve 5 may reducethe pump delivery to one-third of the working deliveryand the reduced delivery is by-passed to the pump inlet. Thereby, theload upon the pump during said intervals is reduced,

with a reduction in discharge pressure from say 1500 lbs. to 175 lbs.per sq. in.

' quickly by pressing the push-button switch 39 to close the circuit ofthe solenoid 34 and cause operation of the device 35 to stop delivery ofsteam to. the turbine 2.

.The delivery valve 1 is designed for closure mainly by hydraulicpressure within the delivery line 6 when the diaphragm motor IT isconditioned by the setting of the air switch 2 for closure of the valve.Also, the angle valve-9 is designed and piped for closure againstthe'stream through the by-pass 8. This is contrary toprior practice andproduces good results. The arrangement of the valve according to priorpractice has been found to cause cavitation, serious erosion andhammering. These faultsareminimized by the reversed arrangement. I U

- The invention .eliminates injurious shock in the operation of thehydraulic apparatus. and

g greatly facilitates control of. the operation By mere setting ofasingle air switch in its .Maximum position '-for. hydraulic. deliverythe delivery valve 1. is caused to open, the by-pass valve 8 is causedto-close and. the rate of deliveryis caused to increase. Another settingof the air switch causes opening of the by-pass valve, reduction ingentle operation of the hydraulic apparatus is obtained and injuriousshock is eliminated.

While the invention is disclosed as employed in connection with decokingapparatus it may be employed advantageously in other services requiringhigh pressure hydraulic delivery. It will of course be understood thatthe present disclosure of the invention is merely illustrative and innowise limiting and that the invention comprehends such modifications aswill fall within the scope of the following claims.

We claim:

1. A pneumatic system for controlling the oper ation of hydraulicapparatus of a type including a pump, a motor for driving same, meansoperable to control the speed of said motor, a charge conduit leading tothe pump inlet, a delivery conduit leading from the pump outlet andhaving a valve, and a by-pass conduit connection leading from saiddelivery conduit, at a point between said valve and the pump, to thepump inlet and having a valve, said pneumatic system comprising an airswitch connected to a compressed air source and settable selectively ata low speed position or a high speed position, pneumatically operabledevices operatively connected to said switch and operatively associatedrespectively, with said two valves and said motor speed control means,and responsive to the low speed setting of the switch to cause openingof the by-pass valve, closing of the delivery conduit valve andreduction of the motor speed, said devices being responsive to thehigh-speed setting of the switch to cause opening of the deliveryconduit valve, closing of the by-pass valve and increase of the motorspeed.

2. A fluid pressure operated system for controlling operation ofhydraulic apparatus of a type including a pump, a motor for drivingsame, means operable to control the speed of said motor, a chargeconduit leading to the pump inlet, a delivery conduit leading from thepump outlet and having a valve, and a by-pass conduit connection leadingfrom said delivery conduit, at a point between said valve and the pump,to the pump inlet, and having a valve, said control system comprising asettable device, and mechanism operable by fluid pressure under controlof said device and responsive to a setting thereof to cause opening ofsaid by-pass valve, closing of said delivery conduit valve and operationof said motor speed control means to cause low speed operation of themotor.

3. A fluid pressure operated system for controlling operation ofhydraulic apparatus of a type including a pump, a motor for drivingsame, means operable to control the speed of said motor, a chargeconduit leading to the pump inlet and a delivery conduit leading fromthe pump outlet and having a valve, said control system comprising afluid pressure switch settable selec- 0 Number tively at a low-speedposition or a high-speed position, and mechanism operable by fluidpressure under control of said switch and responsive to the low-speedsetting of the switch to cause closing of said valve and operation ofsaid motor speed control means to reduce the motor speed, and responsiveto the high-speed setting of the switch to cause opening of said valveand operation of the motor speed control means to increase the motorspeed.

4. A system for controlling the operation of hydraulic apparatusincluding a pump, a motor for driving same, means operable to controlthe speed of said motor, a charge conduit leading to the pump inlet, adelivery conduit leading from the pump outlet and a by-pass conduitconnection leading from said delivery conduit, at a point between saidvalve and the pump, to the pump inlet and having a valve, said controlsystem comprising a switch settable selectively at a low-speed positionor a high-speed position, and mechanism responsive to the low speedsetting of said switch to cause opening of said bypass valve, closing ofsaid delivery conduit valve and operation of said speed control means toreduce the motor speed, said mechanism being responsive also to the highspeed setting of the switch to cause opening of the delivery conduitvalve, closing of the by-pass valve and operation of the speed controlmeans to increase the motor speed.

5. A system for controlling the operation of hydraulic apparatusincluding a pump, a motor for driving same, means operable to controlthe speed of said motor, a charge conduit leading to the pump inlet, adelivery conduit leading from the pump outlet and having a valve, and abypass conduit connection leading from said delivery conduit, at a pointbetween said valve and the pump, to the pump inlet, and having a valve,said control system comprising a manually operable control device, andmechanism responsive to one operation of said device to cause opening ofsaid by-pass valve, closing of said delivery conduit valve and operationof said speed control means to reduce the motor speed, said mechanismbeing responsive also to another operation of said device to causeopening of the delivery conduit valve, closing of the by-pass valve andoperation of the speed control means to increase the motor speed.

WARD J. F. O'CONNOR. FRANK A. BOWEN, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date 2,212,833 Huber Aug. 27, 194p

